1. Field
This invention relates generally to a Fault Current Limiter (FCL).
More particularly the invention relates to a FCL having a one or more magnetisable core limbs bridging the gaps between orthogonally oriented permanent magnets, the core limbs are provided with one or more electrically conductive coils.
2. State of the Art
WO2013/030571 discloses, FCL configurations having one or more magnetisable core limbs bridging the gaps between orthogonally oriented permanent magnets, the limbs being provided with electrically conductive coils. In the embodiment shown in for example in FIGS. 13 and 14, copper shims or plates placed at the sides or above the poles of the permanent magnets in the FCL to allow some protection of the magnets from AC fields generated by the coils.
It has been found that although a degree of shielding can be achieved in this way it is unlikely to be sufficient to divert coil fluxes due to the initial, sub-transient offset fault current which may demagnetise at least a portion of the permanent magnet.
Furthermore other inventive and desirable technical characteristics have been devised in relation to FCLs.